var ___FONTSIZE_SIZES = ['xx-small','x-small','small','medium','large','x-large'];

$(document).ready(function(){
	$('.fontsize-up').click(function(){
		var $body = $('body');
		var current_size = $body.css('font-size');
		
		var size_position = $.inArray(current_size, ___FONTSIZE_SIZES);
		if (size_position != -1) {
			size_position++;
			if (size_position > ___FONTSIZE_SIZES.length-1) {
				return false;
			}
			$body.css('font-size', ___FONTSIZE_SIZES[size_position]);
		} else {
			var num = parseFloat(current_size, 10);
			var unit = current_size.slice(-2);
			var newsize = num * 1.2;
			if (newsize > 50) return false;
			$body.css('font-size', newsize + unit);
		}
		return false;
	});
	
	$('.fontsize-down').click(function(){
		var $body = $('body');
		var current_size = $body.css('font-size');
		
		var size_position = $.inArray(current_size, ___FONTSIZE_SIZES);
		if (size_position != -1) {
			size_position--;
			if (size_position < 0) {
				return false;
			}
			$body.css('font-size', ___FONTSIZE_SIZES[size_position]);
		} else {
			var num = parseFloat(current_size, 10);
			var unit = current_size.slice(-2);
			var newsize = num / 1.2;
			if (newsize < 10) return false;
			$body.css('font-size', newsize + unit);
		}
		return false;
	});
});